Every build has started failing this step.

First failing:
https://ci.chromium.org/p/chromium/builders/luci.chromium.ci/Mac%20FYI%20Retina%20Release%20%28NVIDIA%29/996

Last known good:
https://ci.chromium.org/p/chromium/builders/luci.chromium.ci/Mac%20FYI%20Retina%20Release%20%28NVIDIA%29/995

Chromium regression range according to "parent_got_revision_cp":
http://crrev.com/551019..551069

Not sure if that is the real regression range or not, could use help clarifying that.

Crash seems to be of this form:
Received signal 11 SEGV_MAPERR 6c6261736978
0   Chromium Framework                  0x000000011cd473fc base::debug::StackTrace::StackTrace(unsigned long) + 28
1   Chromium Framework                  0x000000011cd47231 base::debug::(anonymous namespace)::StackDumpSignalHandler(int, __siginfo*, void*) + 2401
2   libsystem_platform.dylib            0x00007fffbbae5b3a _sigtramp + 26
3   ???                                 0x0000000000000048 0x0 + 72
4   CoreFoundation                      0x00007fffa62879c8 -[_CFXPreferences(SearchListAdditions) withSearchListForIdentifier:container:cloudConfigurationURL:perform:] + 152
5   CoreFoundation                      0x00007fffa62b65c4 -[_CFXPreferences appSynchronizeWithIdentifier:container:] + 276
6   CoreFoundation                      0x00007fffa6157561 CFPreferencesAppSynchronize + 49
7   Chromium Framework                  0x000000011a7210bc policy::PolicyLoaderMac::Load() + 44
8   Chromium Framework                  0x000000011a6ebf11 policy::AsyncPolicyLoader::Reload(bool) + 257
9   Chromium Framework                  0x000000011a6ec84c base::internal::Invoker<base::internal::BindState<void (policy::AsyncPolicyLoader::*)(bool), base::WeakPtr<policy::AsyncPolicyLoader>, bool>, void ()>::Run(base::internal::BindStateBase*) + 188
10  Chromium Framework                  0x000000011cd47e33 base::debug::TaskAnnotator::RunTask(char const*, base::PendingTask*) + 323
11  Chromium Framework                  0x000000011ce04d86 base::internal::TaskTracker::RunOrSkipTask(base::internal::Task, base::internal::Sequence*, bool) + 870
12  Chromium Framework                  0x000000011ce06338 base::internal::TaskTrackerPosix::RunOrSkipTask(base::internal::Task, base::internal::Sequence*, bool) + 168
13  Chromium Framework                  0x000000011ce04116 base::internal::TaskTracker::RunAndPopNextTask(scoped_refptr<base::internal::Sequence>, base::internal::CanScheduleSequenceObserver*) + 502
14  Chromium Framework                  0x000000011cdf9fcc base::internal::SchedulerWorker::Thread::ThreadMain() + 796
15  Chromium Framework                  0x000000011ce107ff base::(anonymous namespace)::ThreadFunc(void*) + 95
16  libsystem_pthread.dylib             0x00007fffbbaef93b _pthread_body + 180
17  libsystem_pthread.dylib             0x00007fffbbaef887 _pthread_body + 0
18  libsystem_pthread.dylib             0x00007fffbbaef08d thread_start + 13

Antoine as pixel wrangler, can you help triage?